Integrate profiling into gpui (#8176)

[Profiling](https://crates.io/crates/profiling) crate allows easy
integration with various profiler tools. The best thing is - annotations
compile to nothing unless you request a specific feature.

For example, I used this command to enable Tracy support:
```bash
cargo run --features profiling/profile-with-tracy
```
At the same time I had Tracy tool open and waiting for connection. It
gathered nice stats from the run:

![zed-profiler](https://github.com/zed-industries/zed/assets/107301/5233045d-078c-4ad8-8b00-7ae55cf94ebb)


Release Notes:
- N/A

crates/zed/Cargo.toml

@@ -77,6 +77,7 @@ num_cpus = "1.13.0"
 outline.workspace = true
 parking_lot.workspace = true
 postage.workspace = true
+profiling.workspace = true
 project.workspace = true
 project_panel.workspace = true
 project_symbols.workspace = true